[PATCH] netfilter: xt_owner: Add complementary groups option
DORMANTno replies
From: Lukasz Pawelczyk <hidden>
Date: 2019-04-26 16:02:58
Also in:
lkml, netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The XT_COMPL_GROUPS flag causes GIDs specified with XT_OWNER_GID to be also checked in the complementary groups of a process. Signed-off-by: Lukasz Pawelczyk <redacted> --- include/uapi/linux/netfilter/xt_owner.h | 1 + net/netfilter/xt_owner.c | 23 ++++++++++++++++++++--- 2 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/netfilter/xt_owner.h b/include/uapi/linux/netfilter/xt_owner.h
index fa3ad84957d5..67901269873d 100644
--- a/include/uapi/linux/netfilter/xt_owner.h
+++ b/include/uapi/linux/netfilter/xt_owner.h@@ -8,6 +8,7 @@ enum { XT_OWNER_UID = 1 << 0, XT_OWNER_GID = 1 << 1, XT_OWNER_SOCKET = 1 << 2, + XT_COMPL_GROUPS = 1 << 3, }; struct xt_owner_match_info {
diff --git a/net/netfilter/xt_owner.c b/net/netfilter/xt_owner.c
index 46686fb73784..1c581c14b2ab 100644
--- a/net/netfilter/xt_owner.c
+++ b/net/netfilter/xt_owner.c@@ -91,11 +91,28 @@ owner_mt(const struct sk_buff *skb, struct xt_action_param *par) } if (info->match & XT_OWNER_GID) { + unsigned int i, match = false; kgid_t gid_min = make_kgid(net->user_ns, info->gid_min); kgid_t gid_max = make_kgid(net->user_ns, info->gid_max); - if ((gid_gte(filp->f_cred->fsgid, gid_min) && - gid_lte(filp->f_cred->fsgid, gid_max)) ^ - !(info->invert & XT_OWNER_GID)) + struct group_info *gi = filp->f_cred->group_info; + + if (gid_gte(filp->f_cred->fsgid, gid_min) && + gid_lte(filp->f_cred->fsgid, gid_max)) + match = true; + + if (!match && (info->match & XT_COMPL_GROUPS) && gi) { + for (i = 0; i < gi->ngroups; ++i) { + kgid_t group = gi->gid[i]; + + if (gid_gte(group, gid_min) && + gid_lte(group, gid_max)) { + match = true; + break; + } + } + } + + if (match ^ !(info->invert & XT_OWNER_GID)) return false; }
--
2.20.1